The application of certain organofluorine derivatives as additives to lubricant compositions is known. For example, the use of salts of aliphatic amines and perhalogenated monocarboxylic acids has been described in U.S. Pat. No. 3,565,926. Similarly, the use of the derivatives obtained by the reaction of an aromatic amine and a fluorinated organic compound chosen from fluorinated monocarboxylic acids has been disclosed in French Pat. No. 2,026,493. However, these carboxylic derivatives have the disadvantage of losing their anti-wear efficacy in the presence of traditional additives such as dispersant-detergent additives. This disadvantage is the result of either physiochemical interactions, which prevent their absorption at the surfaces to be lubricated, or of chemical interactions, especially when the dispersant-detergent additives are neutral or overbased salts of alkaline earth metals.
According to French Pat. No. 2,520,377, lubricant compositions possessing exceptional anti-wear properties and an exceptional friction-reducing power have been obtained using, as an organofluorine additive, amines or amino alcohols containing a polyfluorinated chain, and more especially amino alcohols which can be represented by the formula: ##STR2## where n is an integer between 2 and 20 and R is a hydrogen atom or a hydroxyethyl radical. As stated on page 4 of that patent, these amino alcohols, obtained by condensing a 2-(perfluoroalkyl) ethyl iodide with ethanolamine or diethanolamine, occur industrially in the form of mixtures containing a not insignificant proportion (most often from 30 to 50% by weight) of unsaturated amino alcohols of formula: ##STR3## which it is not economical to separate. These unsaturated amino alcohols are also obtained by reacting an olefin C.sub.n F.sub.2n+ 1--CH=CH.sub.2 with an amino alcohol R--NH--CH.sub.2 CH.sub.2 OH (U.S. Pat. No. 3,535,381).
The preceding references are hereby incorporated by reference.
It is now been found that the fluorinated products obtained by hydrogenation of the compounds of the formula (II) or of the industrial mixtures containing them show substantially improved anti-wear efficacy. It has also been found that the derivatives obtained by reaction of the hydrogenated products with an epoxide and/or esterification of these products also, for their part, show an excellent anti-wear efficacy.